JP2001296699A - Electrophotographic toner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electrophotographic toner which can be fixed at a temperature lower than the melting point of the binder resin, and which can save energy. SOLUTION: The electrophotographic toner features ethyl amylopectin prepared through making alcoholic hydroxyl groups of D-glucose, which is the structural element of amylopectin into ethyletherification is used as a binder.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrophotographic toner used in a copying machine, a facsimile, a printer, and the like.

[0002]

2. Description of the Related Art Conventionally, thermal fixing is often used for fixing toner. In general, in the case of heat fixing, the toner to be fixed must be softened or melted by the heat of the fixing device, and the softened or melted toner is subjected to pressure from the fixing device and the fiber of the paper is fixed. The surface of the toner that has been sunk into or softened or melted is sticky, so that the toner adheres by its adhesive force. Therefore, the melting point or softening point of the resin used in the toner needs to be lower than the temperature of the fixing device.

[0003] However, in recent years, the demand for energy saving for the preservation of the global environment is increasing, and the energy that can be consumed by the fixing device is being restricted. Actually, the only way to lower the fixing energy is to lower the temperature of the fixing device, and the resin of the toner corresponding to the fixing device with the reduced fixing energy inevitably has a low melting point. However, the resin whose melting point is lowered in this way tends to become soft, easily block after processing into a toner, or because the surface has tackiness, the interaction with external additives in the toner changes over time and the Changes occur and there is a problem with preservation. Also, since the toner is soft and sticky inside the developing machine, the toner may be spent on the carrier,
There is a problem that the toner is filmed on the developing roller or the toner is fixed on the developing blade. Furthermore, the environment of the printed image may change due to environmental changes.
There is a problem that printing papers are likely to cause blocking. In addition, there is also a problem in the processing of the toner.If the melting point of the conventional resin is lowered, the resin is too soft, so that the toner is difficult to pulverize in the pulverization process and sticks in the pulverizer. There is also a problem.

[0004]

SUMMARY OF THE INVENTION The present invention solves the above-mentioned problems, namely: a: energy saving by lowering the fixing temperature compared to the conventional one; and b: using a conventional low melting point resin. C: Does not change with time in the interaction with an external additive compared to a toner using a conventional low melting point resin. D: To a toner using a conventional low melting point resin. No toner spent, filming, and sticking occur. E: Improves the storage stability of the printed material compared to a toner using a conventional low-melting resin. F: Good compared to a toner using a conventional low-melting resin. An object of the present invention is to provide an electrophotographic toner having characteristics such as obtaining pulverizability.

[0005]

As a result of various studies to solve the above-mentioned problems, the present inventor has found that a binder resin having a melting point higher than the minimum temperature for fixing the toner and a wax having a melting point lower than the minimum temperature for fixing the toner. By using the wax as a solvent or a plasticizer for the binder resin in a liquid state at a temperature equal to or higher than the melting point of the wax, the binder resin is dissolved at the molecular level by the wax, and the resin is softened or dissolved. As a result, it has been found that the toner can be fixed at a temperature lower than the melting point of the binder resin, and the present invention has been completed.

In the present invention, by employing the toner system as described above, it is possible to fix the toner at a temperature near the melting point of wax, which is much lower than the melting point of the resin actually used as the binder resin, thereby saving energy. Was.
Further, in the present invention, by adopting the toner system as described above, a toner which can be fixed at a low temperature even when a binder resin having a high melting point, particularly, ethyl amylopectin is used was obtained.

Conventionally, a method of using a wax dispersed in a resin of a toner is known. This is done by dispersing wax in the resin in the toner so that the toner does not adhere to the fixing roller, and when dispersing, the dispersed wax oozes out to improve the releasability between the toner and the fixing roller. I have. However, conventionally used resins are not soluble in wax, and therefore cannot dissolve or soften the resin itself.

On the other hand, ethyl amylopectin used as a binder resin in the present invention is dissolved or plasticized in a liquid state wax at a temperature higher than the melting point of the wax, and thus has an effect which is clearly different from that of a conventional binder resin. It is.

In the present invention, the melting point of the resin refers to the softening point according to the flow tester method, and the melting point of the wax in the present invention refers to the point at which the crystals of the wax become almost amorphous and become transparent. It indicates the melting point of a concept different from the top peak of Tg or endotherm.

Hereinafter, means for solving the problems of the present invention which can be achieved based on the above knowledge will be described. In addition, amylopectin will be described as an example of a high melting point binder resin employed in the present invention, but the high melting point binder resin employable in the present invention is not limited to amylopectin.

A first aspect of the present invention is a toner for electrophotography, wherein ethyl amylopectin obtained by ethyl etherifying an alcoholic hydroxyl group of D-glucose, which is a component of amylopectin, is used as a binder.
A second aspect of the present invention is the first electrophotographic toner, wherein the toner can be fixed at a temperature equal to or lower than the melting point of ethyl amylopectin by mixing ethyl amylopectin and a wax. A third aspect of the present invention is the first or second electrophotographic toner, characterized in that ethyl amylopectin is dissolved in wax at a temperature equal to or higher than the melting point of the wax as a solvent.

A fourth aspect of the present invention is the first to fourth electrophotographic toners, wherein ethyl amylopectin accounts for 10 wt% or more of the total weight of the binder. A fifth aspect of the present invention is the first to fourth electrophotographic toners, wherein the composition ratio of the wax to ethyl amylopectin is 97: 3 to 5:95. Sixth Embodiment
Wherein the melting point of wax is lower than the melting point of ethyl amylopectin.

A seventh aspect of the present invention is that the wax has a melt viscosity of 1
1 to 1,000,000 cpois at 50 ° C
e, the first to sixth electrophotographic toners. An eighth aspect of the present invention is the first to seventh electrophotographic toners, wherein the average molecular weight of ethyl amylopectin is 10 ⁴ to 10 ⁸ . Ninth Embodiment of the Present Invention
Are the first to seventh electrophotographic toners, wherein the degree of ethoxyl substitution of ethyl amylopectin is 1 to 3 on average.

In a tenth aspect of the present invention, the wax has a penetration at 25 ° C. of 0 to 20.
To ninth electrophotographic toner. Eleventh of the present invention,
Wherein the wax is at least one selected from the group consisting of paraffin, microcrystalline, olefin, and oxidized wax thereof.
0 for the electrophotographic toner.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the electrophotographic toner of the present invention will be described in more detail. In the toner of the present invention,
As the main binder, ethyl amylopectin having a high melting point and excellent storage stability, anti-spent, filming and anti-adhesion properties is used, and this is dissolved in wax to solidify to form a toner. Therefore, when the toner is subjected to thermal fixing, ethyl amylopectin is dissolved by the wax at a temperature equal to or higher than the melting point of the wax, and even if the temperature does not reach the melting point of the ethyl amylopectin, the ethyl amylopectin is softened or dissolved to exhibit fixing performance. Since the melting point of ethyl amylopectin itself is high, the resin is not too soft, and good pulverizability can be obtained.

In the present invention, when ethyl amylopectin is mixed with a conventional resin, it is preferable that the content of ethyl amylopectin in the entire resin is at least 10 wt% in the binder composition ratio as described in the fourth aspect. . If the content of ethyl amylopectin is less than 10% by weight of the total weight of the binder, the melting point of the toner mixed with the conventional resin cannot be sufficiently lowered, resulting in poor fixing.

As for the composition ratio of wax to ethyl amylopectin, the higher the amount of wax, the lower the dissolving viscosity of ethyl amylopectin, but if the amount of ethyl amylopectin decreases, the wax dissolves other resins. Since the resin does not mix with the resin, the resin and the wax are separated, and it is difficult to form a toner. If the amount of ethyl amylopectin is large and the amount of wax is small, even if ethyl amylopectin is dissolved in the wax, the dissolution viscosity is too high and the fixing performance is not good.

The present inventors have conducted intensive studies on the composition ratio of wax to ethyl amylopectin.
The composition ratio of ethyl amylopectin and wax is the same as that of the fifth embodiment.
As described above, when the composition ratio of the two is 97: 3 to 5:95, it is clear that good fixing performance can be obtained.
However, practical use is not limited to fixing only in an air-conditioned place such as an office, and various fixing environments such as high temperature, low temperature, high humidity, and low humidity can be considered.
5:20:80, even more preferably 90:10.
~ 30: 70, more preferably 80: 20 ~ 40: 6
0.

If a wax having a melting point lower than that of ethyl amylopectin is not used, the wax does not melt at a temperature lower than the melting point of ethyl amylopectin, so that ethyl amylopectin cannot be dissolved by the wax, and the melting point of the toner can be lowered. Can not. Therefore, the melting point of the wax is preferably from 50 ° C to 130 ° C, more preferably from 50 ° C to 110 ° C, even more preferably from 50 ° C to 100 ° C, and most preferably from 50 ° C to 90 ° C.

The lower the melt viscosity of the wax, the better, but there is no knowledge of a wax that cuts below 1 cpoise. Conversely, if the melt viscosity of the wax is high, when ethyl amylopectin is dissolved with wax, the Since the wax solution has a high viscosity, the melt viscosity is too high, and fixing failure is likely to occur. Therefore, the wax viscosity is 1 to 10,000,000 at 150 ° C.
It has been found that wax such as cpoise is preferable, but practical use is not limited to fixing only in an air-conditioned place such as an office.
Since use in various fixing environments such as low humidity is conceivable, it is still more preferably 1 to 10,000 cpoise, still more preferably 1 to 1,000 cpoise,
Considering the margin, more preferably 1 to 100 c
Poise.

As a result of examining the molecular weight of ethyl amylopectin used in the present invention, the average molecular weight was found to be 10 ⁴ to 10 ^8.
It was clear that good fixing quality could be obtained. However, when the molecular weight is small, the viscosity when dissolved with wax is low, and when the molecular weight is large, the dissolved viscosity when dissolved with wax is high, so the smaller the molecular weight, the smaller the amount of wax used. However, if the molecular weight is too small, the resin becomes too hard, the toner becomes brittle and easily cracked, and is easily crushed excessively. Conversely, if the molecular weight is large, the melt viscosity when dissolved with the wax increases, and the amount of the wax must be increased, so that the flexibility becomes too high and the pulverizability deteriorates. Therefore, in order to improve the pulverizability and the fixability in a better direction, the more preferable molecular weight is 10 ⁵ to 10 ⁷ .

There are several methods for determining the molecular weight, utilizing the fact that the molecular weight is proportional to the viscosity, and dissolving ethyl amylopectin in a solvent to express the molecular weight by the viscosity of the solution, a method of expressing the molecular weight by an equivalent using a chemical, and the like. There are also
The present invention is not affected by the measurement method. In addition, as a result of examining the degree of ethoxyl substitution of ethyl amylopectin, it was revealed that if the degree of substitution was 1 to 3 on average, good properties as ethyl amylopectin could be exhibited. If the degree of ethoxyl substitution is low, the solubility in wax is lost, and the number of alcoholic hydroxyl groups is 3 in the D-glucopyranose structural unit.
Is the upper limit, but a more preferable value of the degree of ethoxyl substitution is 1.5 to 3 on average, and still more preferably 2 or more and 3 or less.

As a result of examining the penetration at 25 ° C. of the wax used in the present invention, it was found that a wax having a penetration of 0 to 20 at 25 ° C. can be preferably used in the present invention. . Generally, if the penetration of the wax is high, the tackiness of the wax itself becomes high, so that it is easy to cause spent, filming, sticking, etc. in the development design, which is not preferable. Therefore, considering the use in a high temperature environment, the penetration of the wax is considered. Is preferably from 0 to 8, more preferably from 0 to 5.

The waxes usable in the present invention include the following. Paraffin, microcrystalline wax, or their oxidized wax, montanic acid, montanic acid ester, carnauba, candelilla, rice, esparto, caster, wood wax, beeswax, jojoba, sterols, ketones and the like can be used. Although the type of these waxes does not essentially affect the effect of the present invention, the wax used in the present invention includes at least one selected from the group consisting of paraffin, microcrystalline, olefin, and oxidized waxes thereof. Good to use. It has been clarified that when these waxes are used, ethyl amylopectin has high solubility in ethyl amylopectin and the ethyl amylopectin dissolves in the wax in a short time when a toner is produced. This is probably because the paraffin, microcrystalline, olefin, or oxidized wax thereof has a particularly low polarity and is well compatible with the ethoxyl group of ethyl amylopectin. Further, each of the waxes may be used alone, or two or more kinds may be used in combination.

The characteristics of ethyl amylopectin used in the present invention will be further described in comparison with its precursor amylopectin. Generally, amylopectin does not melt by heat because it has a very large hydrogen bonding force due to a hydroxyl group in the molecule and very high crystallinity. Further, basically, there is hardly any resin dissolved in the wax, and amylopectin, which is a precursor of ethyl amylopectin in the present invention, is naturally insoluble in the wax and completely insoluble in organic solvents.

As described above, the reason that amylopectin is fundamentally insoluble in heat and insoluble in wax and various organic solvents is that the alcoholic hydroxyl group of the D-glucopyranose unit itself has too strong a hydrogen bond. Therefore, the bonding force between the molecules is very large and the crystallinity is high, which results in that the molecular chains are rigid and cannot be unraveled. Also,
Particularly, since the hydroxyl group itself has a very high polarity with respect to the wax, a relatively low-polarity wax does not have any solubility because the polarity is too different.

In general, wax is composed of linear paraffin, slightly branched microcrystalline, olefin, fatty acid,
There are aliphatic esters, aliphatic ketones, amines, amides, alcohols, sterols, etc., but these are only partial bonds or groups of the molecule, and the main alkyl group is very long, so the polarity as a whole is Extremely low.

On the other hand, ethyl amylopectin has a D
-Glucopyranose having an α- (1 → 4) bond,
Amylopectin, which is considered to have a dendritic structure branched by α- (1 → 6) bonds, has a form in which three or more alcoholic hydroxyl groups of D-glucopyranose unit are partially or entirely substituted with ethoxyl groups. It is thought that it was synthesized as a new kind of resin completely different from amylopectin by blocking the hydroxyl group in the molecule with an ethoxyl group to cut off the hydrogen bond between the molecules by this hydroxyl group and lowering the crystallinity. There are obvious differences in physical and chemical properties. For example, in terms of physical properties, unlike amylopectin, it has a melting point and is thermoplastic. The chemical properties include solubility in various organic solvents and waxes. These differences are crucially different from the original amylopectin, are no longer of the same family, and fall into the category of new synthetic resins.

The reason for the expression of the solubility of ethyl amylopectin in wax is that, as described above, ethyl amylopectin is obtained by substituting a part or all of the alcoholic hydroxyl group of the D-glucopyranose unit with an ethoxyl group, thereby reducing the number of hydrogen bonding points. The crystallinity is reduced, and the polarity of the ethoxyl group is low, so that the affinity for the low-polarity wax is increased and the ethoxyl group is dissolved in the wax.

As an example of the method for producing ethyl amylopectin used in the present invention, a method represented by the following chemical formula 1 can be mentioned. Alkaline amylopectin is prepared from amylopectin as a raw material, and is treated with ethyl chloride in a pressure can, washed with hot water and dried. Amylopectin consists of a chain of anhydroglucose, where each C6 unit has three replaceable O
Although having an H group, ethyl amylopectin partially or completely etherifies the OH group with ethyl chloride.
Ethyl etherification of amylopectin is carried out in the range from the case of substitution degree 1 shown by the following formula (1) to the case of substitution degree 3 shown by the following formula (2).

[0031]

Embedded image C ₆ H ₇ O ₂ (OH) ₂ ONa + ClC ₂ H ₅ → C ₆ H ₇ O ₂ (OH) ₂ OC ₂ H ₅ + NaCl (1) C ₆ H ₇ O ₂ (ONa) ₃ +3 ClC ₂ H ₅ → C ₆ H ₇ O ₂ (OC ₂ H ₅ ) ₃ + 3NaCl (2)

The following are examples of the sub-resin of the binder resin that can be used in the present invention. Styrene such as polystyrene, poly p-chlorostyrene, polyvinyltoluene and a substituted homopolymer thereof; styrene-
p-chlorostyrene copolymer, styrene-propylene copolymer, styrene-vinyltoluene copolymer, styrene-vinylnaphthalene copolymer, styrene-methyl acrylate copolymer, styrene-ethyl acrylate copolymer,
Styrene-butyl acrylate copolymer, styrene-octyl acrylate copolymer, styrene-methyl methacrylate copolymer, styrene-ethyl methacrylate copolymer,
Styrene-butyl methacrylate copolymer, styrene-α
-Methyl chloromethacrylate copolymer, styrene-acrylonitrile copolymer, styrene-vinyl methyl ketone copolymer, styrene-butadiene copolymer, styrene-isoprene copolymer, styrene-acrylonitrile-indene copolymer, styrene- Styrene-based copolymers such as maleic acid copolymer and styrene-maleic acid ester copolymer; polymethyl methacrylate, polybutyl methacrylate, polyvinyl chloride, polyvinyl acetate, polyester, polyurethane, polyamide, epoxy resin, polyvinyl butyral, Polyacrylic acid resins, rosins, modified rosins, terpene resins, aliphatic or alicyclic hydrocarbon resins, aromatic petroleum resins, chlorinated paraffins, etc., can be used alone or in combination, but especially for these resins In limiting There. If necessary, carbon black or a color pigment may be kneaded and dispersed in the resin, and the charge control agent may be used in combination. After pulverization, additives such as silica, titanium, and strontium may be added to adjust the fluidity of the toner.

Japanese Patent No. 2597452 discloses a composition similar to the composition of the present invention in that it contains the above-mentioned components.
The publication states that a plant wax is added to a cellulose-chitosan-based or pullulan-chitosan-based copolymer derived from plants and animals as a biodegradable resin. However, cellulose, chitosan, pullulan, copolymers of cellulose and chitosan, and copolymers of pullulan and chitosan all have no thermoplasticity, and fixing with heat is impossible with these resins alone, and as described above, wax and various organic solvents are used. It is a system insoluble in Therefore, in this system, fixing can be performed only by the thermal melting property of the wax in a state where these resins are dispersed like a pigment without being dissolved in the wax. As described above, amylopectin and ethyl amylopectin are substances having completely different physical and chemical properties. Therefore, the present invention is an invention in which a fixing mechanism for completely dissolving a binder resin with wax, and fixing and binding with the dissolved binder resin, and a binder resin used are fundamentally different.

Similarly, there is JP-A-62-94853, and the claims include ethylamylopectin.
However, the present invention is configured to increase the cohesive strength of the resin by mixing ethyl amylopectin and the like into another binder resin, and does not use ethyl amylopectin as the main resin as in the present invention, but rather uses the present invention. In the case of the invention, since the wax dissolves ethyl amylopectin, the viscosity decreases, and conversely, the cohesive strength tends to decrease. In addition, since the fixing is performed by the conventional resin, the fixing temperature is high.

On the other hand, in the present invention, ethyl amylopectin is used as the main resin, and the fixing performance can be fixed at a low temperature by dissolving the ethyl amylopectin with wax. Therefore, it is another invention which is fundamentally different from the present invention.

[0036]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be specifically described below based on embodiments.

Example 1 Ethyl amylopectin 78 wt% Sasol H 2 16 wt% Carbon black 5 wt% CCA (charge control agent) 1 wt%

Example 2 Ethyl amylopectin 50 wt% Sasol H2 10 wt% Magnetic substance 39 wt% CCA 1 wt%

Example 3 Ethyl amylopectin 72 wt% Carnauba wax 22 wt% Carbon black 5 wt% CCA 1 wt%

Example 4 Ethyl amylopectin 72 wt% montanic acid ester 39 wt% carbon black 5 wt% CCA 1 wt%

Example 5 Ethyl amylopectin 78 wt% 155 F ° paraffin 16 wt% carbon black 5 wt% CCA 1 wt%

Example 6 Ethyl amylopectin 74 wt% Rice wax 20 wt% Carbon black 5 wt% CCA 1 wt%

Example 7 Ethyl amylopectin 74 wt% oxidized paraffin 20 wt% carbon black 5 wt% CCA 1 wt%

Example 8 Ethyl amylopectin 94 wt% carbon black 5 wt% CCA 1 wt%

Example 9 Ethyl amylopectin 74 wt% oxidized paraffin 20 wt% cyan 5 wt% CCA 1 wt%

Example 10 Ethyl amylopectin 72 wt% Carnauba 22 wt% Yellow 5 wt% CCA 1 wt%

Example 11 Ethyl amylopectin 42 wt% High melting point polyester (melting point 155 ° C.) 30 wt% Carnauba 22 wt% Carbon black 5 wt% CCA 1 wt%

Example 12 High-melting polyester (melting point: 155 ° C.) 94 wt% carbon black 5 wt% CCA 1 wt%

Example 13 Low melting point polyester (melting point 94 ° C.) 94 wt% carbon black 5 wt% CCA 1 wt%

Example 14 High melting point polyester (155 ° C.) 78 wt% Sasol H2 16 wt% Carbon 5 wt% CCA 1 wt%

The above Examples 1 to 13 were kneaded five times with three rolls, cooled and pulverized, and 1 part of silica was added as an external additive to 100 parts of the toner and mixed to obtain a final toner. In Example 14, the wax and the resin were separated from each other and could not be formed into a toner.

When an experiment was conducted using these toners while actually changing the temperature of the fixing machine, the results shown in Table 1 below were obtained. It is not necessary to apply oil to the fixing roller for the formulation containing wax, but oil was applied to the roller for all toners in order to unify the conditions.

[0053]

[Table 1]

In the case of using only ethyl amylopectin and in the case of using only the high melting point polyester (155 ° C.), fixing will not be performed unless a temperature of 160 ° C. or more is applied. Was completed.

When a storage test was performed using the above toner, the results shown in Table 2 below were obtained. (Storage environment 40 ℃ 2
weekly)

[0056]

[Table 2]

The symbol ○ indicates that there is no change. The charge amount indicates the charge amount on the sleeve for one-component development. OP
C: For background contamination, remove the toner adhered to the OPC with a transparent adhesive tape, paste it on white paper, measure the density ID1 with a Macbeth reflection densitometer, and further place a transparent adhesive tape without toner on white paper. Paste the density ID
2 is the difference between the measured values, and the smaller the value, the less the stain. From the results of ΔID = ID1−ID2 and above, it can be seen that the storage stability and properties of the ethyl amylopectin and the wax were not changed even though the melting point was reduced with ethyl wax. In addition, there is no problem in the storability of ordinary high melting point polyesters, and the properties are slightly changed but not at a problem level. However, those using low-melting-point polyester completely solidify in a storage test, and their properties cannot be measured even.

Temporal change after running of toner (after 2,000 sheets of images) Image formation is performed by one-component development, and the charge amount is the charge amount of the toner on the sleeve.

[0059]

[Table 3]

From the above results, in the case of ethyl amylopectin alone or the combination of ethyl amylopectin and wax, there is almost no change in the charge amount, and there is almost no change in the background stain. With the combination of ethyl amylopectin and the high melting point polyester, a slight change in the charge amount and deterioration of the background stain can be seen, but at a level that does not cause any problem. In the case of the high melting point polyester alone, there is a decrease in the charge amount and an increase in background stain, but this is not a level that cannot be used. If the low melting polyester alone is used, the charge amount is greatly reduced and the background stain is deteriorated, so that the level cannot be used.

Further, a test in an image forming system was performed. The toner spent was tested by two-component development, and the developing roller filming and the fixing of the developing blade were tested by one-component development, and evaluation was performed after 2,000 images were output for both one-component and two-component development.

[0062]

[Table 4]

In the system of ethyl amylopectin or the combination of ethyl amylopectin and wax, there was almost no change from the initial quality. In the case of the combination of ethyl amylopectin and high melting point polyester, filming of the developing roller slightly occurs, but this does not cause any problem on the image. In the case of high-melting-point polyester alone, toner spent on the carrier in two-component development, developing roller filming in one-component development,
Although toner sticking to the developing blade is slightly observed, it is not a problematic level but a conventional performance. In the case of low melting polyester, toner spent in two-component development, 1
Vigorous toner adhesion is observed in both the developing roller filming and the toner fixation to the developing blade in the component development.
At this time, various abnormal images such as uneven image density, background stain on the transfer paper, and vertical white stripes of the image are observed on the image, and this system cannot be used from the viewpoint of image quality.

Next, regarding the storability of the printed material, tests were conducted separately for both one-sided printing and two-sided printing.

[0065]

[Table 5]

As described above, only when the low-melting-point polyester of Example 13 was used, transfer paper was contaminated and blocked, so that the transfer paper could not be used. Further, the pulverizing step in forming the toner was evaluated. The following is an evaluation of the time required for a certain amount of toner to be completed as a toner having a desired particle size and the state of adhesion.

[0067]

[Table 6]

As described above, it can be said that Examples 1 to 12 have almost no problem in the process. However, in the system using the low-melting-point polyester of Example 13, the pulverization time is twice or more than usual, and the toner adheres severely in the pulverization chamber, and the pulverization conditions change during the pulverization. Therefore, it can be said that a low melting point polyester system has a serious problem in toner processing.

[0069]

(1) It is possible to provide a toner which can be fixed at a temperature lower than the melting point of ethyl amylopectin, thereby saving energy. (2) Even if the toner has a low melting point, since the melting point of ethyl amylopectin itself is high, a toner having improved storage stability is provided. (3) Since ethyl amylopectin is a hard resin, there is provided a toner in which the external additive does not sink into the toner or the external additive is not contaminated by the low molecular weight resin, and the change in characteristics can be minimized. (4) By using hard and non-tacky ethyl amylopectin, a toner can be provided which can prevent toner spent, filming, sticking and the like. (5) The use of ethyl amylopectin having a high melting point and being hard and non-tacky provides a toner in which a printed material is not blocked. (6) Even though the low melting point toner is used, ethyl amylopectin used is not too soft and moderately hard, so that a toner which can be crushed well is provided.

Claims (11)

[Claims] 1. A toner for electrophotography, wherein ethyl amylopectin obtained by ethyl etherifying an alcoholic hydroxyl group of D-glucose, which is a component of amylopectin, is used as a binder. 2. The electrophotographic toner according to claim 1, wherein the toner can be fixed below the melting point of ethyl amylopectin by mixing ethyl amylopectin with a wax. 3. The method according to claim 1, wherein the ethyl amylopectin is added to the wax.
The electrophotographic toner according to claim 1, wherein the wax is dissolved as a solvent at a temperature equal to or higher than the melting point of the wax. 4. The method according to claim 1, wherein ethyl amylopectin accounts for 10% by weight or more of the total weight of the binder.
4. The toner for electrophotography according to any one of claims 1 to 3. 5. The electrophotographic toner according to claim 1, wherein the composition ratio of the wax to ethyl amylopectin is from 97: 3 to 5:95. 6. The electrophotographic toner according to claim 1, wherein the melting point of the wax is lower than the melting point of ethyl amylopectin. 7. The electrophotographic toner according to claim 1, wherein the wax has a melt viscosity of 1 to 1,000,000 cpoise at 150 ° C. 8. An ethyl amylopectin having an average molecular weight of 1
The toner for electrophotography according to any one of claims 1 to 7, wherein the toner number is from 0 ⁴ to 10 ⁸ . 9. The method according to claim 1, wherein the degree of ethoxyl substitution of ethyl amylopectin is 1 to 3 on average.
The toner for electrophotography according to any one of the above. 10. A wax having a penetration at 25 ° C. of 0.
The electrophotographic toner according to any one of claims 1 to 9, wherein 11. The toner according to claim 1, wherein the wax is at least one selected from the group consisting of paraffin, microcrystalline, olefin, and oxidized waxes thereof.